fix: compilation without NTL
Merge pull request #621 from mmklee/nontl

fix: compilation without NTL
prepare for singular 4-1: cring (currently inactive)
add: Singular/nuber2.*: handling of NUMBER2, CRING etc.
"fix" the SI==3 case in rintegers and add the missing bits in rmodulon
again
Try a short patch to keep it simple
re-stablish the Order module. Containing also a 1st draft for lattices
chg: Singular/dyn_modules/Order/singular.cc depends on SINGULAR_4_1
Merge branch 'spielwiese' of github.com:Singular/Sources into spielwiese

Conflicts:
	Singular/dyn_modules/Order/singular.cc
	Singular/ipassign.cc
	Singular/ipshell.cc
	Singular/number2.cc
	Singular/number2.h
	Singular/subexpr.cc
	Singular/table.h
syntax fix, reset ipshell.cc